IT'S NOT the size of the footballer in the fight, it's the size of the fight in the footballer. 

This adaptation of Mark Twain's famous quote perfectly sums up Collingwood's resident tagger, 163cm midfielder Brittany Bonnici. 

Bonnici's reputation as an expert stopper continues to grow, a process that was accelerated with her latest blanketing job on reigning AFL Women’s best and fairest Emma Kearney last Saturday night. 

Kearney still won 15 possessions, but the Magpie charged with dulling her influence racked up 21 of her own, including 16 contested, plus four clearances and 10 tackles.

North Melbourne came out on top by 22 points, but Bonnici was arguably best afield. 

It was her follow-up act after doing a similarly good job on Kearney last year (when Kearney was playing for the Bulldogs), a week after limiting AFLW superstar Daisy Pearce to only nine disposals in her tagging initiation. 

"I'm not going to deny the fact I'm pretty proud of my efforts. If I get a job (again) next week, I just want to top it," Bonnici said with a wide grin. 

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Collingwood coach Wayne Siekman raves about how "strong minded" Bonnici is, and joked her performance against the finals-bound Roos might even result in the Lions putting time into her at Victoria Park on Sunday.

The 22-year-old, who took great satisfaction at catching Kearney in bruising tackles a few times, offered a basic explanation for her tagging success.

"When the footy's there, it's me and Kearney and she's taking me to the ball…I just take each challenge as it comes and it's a one-versus-one competition," Bonnici said.

"It really excites me when Wayne comes to me and gives me these roles and I just know I'm going to get better. 

"The reality is once the footy's there to be won, you're either going to win it, halve it or lose it – and my mentality is I don't want to be beaten. It's as simple as that." 

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As for the trademark helmet that makes Bonnici a standout on the ground, there is a back story for that, too. 

She could have been lost to football just as an elite pathway for females was opening up, having taken a year off to recover from repeat concussions in a short period. 

"I started to get a few hits to the head and things weren't going too well, so I went to the doctors and they thought the best thing for me to do was to take some time off footy," Bonnici said. 

"That's what I did and they let me know what I needed to do to get back, and in that time AFLW was announced and my mindset straightaway flipped. 

"I knew what I wanted to get and I was going to get it, and if that meant wearing a helmet, then so be it,” she said,

"It's also a good opportunity for me to take a stand on concussion and make sure people are starting to take it seriously, which I think the AFL is with everything they're putting in place."